Photosensitive silver halide element containing a thiosugar antifoggant

ABSTRACT

A photographic element comprising a support having thereon one or more layers at least one of which is a light-sensitive silver halide emulsion layer, said element contains at least one of certain thiosugars in an amount effective to inhibit fog.

United v States Patent 11 1 1 Sakamoto et al. a

PHOTOSENSITIVE SILVER HALIDE ELEMENT CONTAINING A THIOSUGAR ANTIFOGGANT Assignee: Konishiroku Photo Industry Co.,

Ltd., Tokyo, Japan Filed: Mar. 29, 1972 Appl. N6; 239,343

u.s."c|. 96/76 R, 96/109 Int. Cl G03e l/34, G03c 1/76 Field of Search 96/109,'107, 76 R 'Oct. 30, 1973 [56] References Cited UNITED STATES PATENTS 3,635,717 l/1972 Ohi et al. 96/108 3,297,446 l/1967 Dunn 96/107 3,475,175 10/1969 King et al. 96/109 Primary Examiner-Norman G. Torchin Assistant Examiner-Won H. Louie, Jr.

.Attomey -lordan B. Bierman et al.

57 ABSTRACT A photographic element comprising asupport having thereon one or more layers at least 'oneof which is a light-sensitive silver halide emulsion layer, said element contains at least one of certain thiosugars in an amount effective to inhibit fog 9 Claims, No Drawings I This invention relates to light-sensitive silver halide photographic materials containing certain thiosugars.

When developed at relatively high temperatures, light-sensitive silver halide photographic materials tend to suffer from fogging, in general. This phenomenon is considered ascribable to the fact that the activation energy required for the development of fog is greater than that required for the development of photographic image. Accordingly, the development of photographic materials at elevated temperatures is not so desirable. As the quick processing of light-sensitive photographic materials have been demanded recently, however, the time required for development is intended to be shortened. Owing to such quick development, it has been found that many substances, which have'been effectively used as antifoggants hitherto, have various drawbacks in practice. For example, there are encountered the cases where a certain compound, when used in an amount within a range capable of sufficiently inhibiting the formation of fog at the time of high temperature development; brings aboutsuch'drawbacks as to greatly decrease the speed, or to degrade the developability, of the resulting photographicr'naterial, or to cause, in the case of a color photographic material, insufficient bleaching of metallic silver after color development of the photographic material.

An object of the present invention is to provide lightsensitive silver halide photographic materials suitable for quick development at elevated temperatures.

Another object of the invention is to provide lightsensitive silver halide photographic materials which scarcely form fog even when the development time is prolonged.

A further object of the invention is to provide lightsensitive silver halide photographic materials which are less in variation of photographic properties even when stored for a long period of time.

Other objects and advantages 'of the invention will become apparent from the description made hereinbelow.

In accordance with the present invention, there are provided light-sensitive silver halide photographic materials containing thiosugars of the general formula,

ococn ococu. ococn j wherein R, is a hydrogen-atom,an alkyl group, or'a group of the formula (where Y and Z are individually an alkyl, aryl or aralkyl group); R is a hydrogen atom or a group of the formula -CH OR (where R is an acyl group). F urther, all the stereoisomers with respect to C to C are included by the thiosugars.

When one or more of the above-mentioned thiosugars are incorporated into at least one of the layers (e.g. emulsion layer, sub layer, protective layer, backing layer orthe like) of a light-sensitive silver halide photographic material, said photographic material is successfully inhibited from formation of fog to make it possible to accomplish the above-mentioned objects ofthe present invention. That is, even when the said photographic material is subjected to high temperature treatment, not only the formation of fog and the formation of stains (stains formed by reaction of couplers contained in the photographic material with an oxidation product of the developer used for the development'thereof) can effectively be inhibited, but also the tendency of forming'said fog and stains can successfully be suppressed even when the development time is prolonged.

The thiosugars of the aforesaid general formula can be synthesized according to, for example, the process disclosed in Journal of the American Chemical Society, 2598 (1958). Typical examples of said thiosugars are as follows: Y

. Triacetyl-L-arabinose isothiuronium bromide Triacetyl-D-xylose isothiuronium bromide LMethylthio-D-xylose triacetate Amyl triacetyl-L-arabinose xanthate l-Mercapto-D-xylose triacetate Benzyl triacetyl-L-arabinose xanthate Ethyl triacetyl-D-xylose xanthate Amyl tetraacetyl-D-mannose xanthate Butyl tetraacetyl-D-glucose xanthate l-Mercapto-D-glucose tetraacetate l-Acetylthio-D-mannose tetraacetate Tetraacetyl-D-glucose isothiuronium bromide Benzyl triacetyl-D-ribose xanthate m-Tolyl tetraacetyl-D-glucose xanthate Ethyl triacetyl-D-ribose xanthate l-Methylthio-D-glucose tetraacetate l-Acetylthio-D-ribose triacetate l-Mercapto-D-mannose tetraacetate Phenyl tetracetyl-D-mannose-xanthate l-Laurylthio-D-mannose tetraacetate 21. l-Benzoylthio-D-glucose tetraacetate Typical procedures for synthesizing the abovementioned thiosugars are set forth below with reference to synthesis examples.

SYNTHESIS EXAMPLE 1 Synthesis of n-butyl tetraacetyl-D glucose xanthate [theexemplified compound (9)]:

lQInto a mixture comprising 12 g. of D-glucose and 46.8 cc. of acetic anhydride were dropped several drops of concentrated sulfuric acid. After heating the mixture over a water bath for 2 hours, acetic acid was removed by distillation under reduced pressure. The residue was poured into ice water, and the resulting liquid was stirred to deposit crystals. Subsequently, the crystals were recovered by filtration, washed with water and then dried to obtain D-pentaacetyl glucose, yield 20.4 g.

2. A mixture comprising 10 g. of the thus obtained D-pentaacetyl glucose, 10 cc. of a 30 percent hydrogen bromide-acetic acid solution and 5 cc. of acetic acid was stirred at room temperature for 2 hours in a means shielded from moisture, and then gradually dropped into ice water, which was kept with vigorous stirring, to deposit crystals. The crystals were quickly collected by filtration and immediately transferred into ether. The resulting ether solution was washed with a dilute aqueous sodium bicarbonate solution and dried over sodium sulfate, and then the ether was removed by distillation under reduced pressure. The residue was extracted with petroleum ether, and the extract was cooled to deposit crystals, which were then recovered by filtration and dried under reduced pressure to obtain D- acetobromoglucose in the form of white crystalline needles, m.p. 88-89C., yield 4 g.

3. 2 Grams of the thus obtained D-acetobromoglucose was added to a suspension of 0.9 g. of potassium n-butyl xanthate in 10 cc. of ethanol, and the suspension was refluxed over a water bath for 10 minutes. After cooling, the liquid reaction mixture was poured into 60 cc. of water, and then cooled to deposit crystals. Subsequently, the crystals were recovered by filtration, washed with water, dried under reduced pressure and then recrystallized from a small amount of ethanol to obtain butyl D-tetraacetyl glucose xanthate in the form of pale yellowish white crystals, m.p. 1l5-l16C., yield 1.7 g.

Elementary analysis for C M- 0, 8

Found C: 47.51 H: 6.01 S: 12.68

Calculated C: 47.49 H: 5.87 S: 13.3.5 Synthesis Example 2 Synthesis of tetraacetyl-D-glucose isothiuronium bromide [the exemplified compound (12)]:

A mixture comprising 2 g. of D-acetobromo-glucose, 0.4 g. of thiourea and 4 cc. of acetone'was refluxed over a water bath for 15 minutes, and then cooled to deposit crystals. The crystals were dissolved in 150 cc. of acetone, and the resulting solution was subjected to filtration to remove insoluble matters. Thereafrer, the filtrate was concentrated under reduced pressure to one-third the original volume, and then cooled to deposit crystals. Subsequently, the crystals were recovered by filtration and dried under reduced pressure to obtain tetraacetyl-D-glu cose isothiuronium bromide in the form of white crystals, m.p. 204C., yield 0.6 g.

Elementary analysis for C H N O BrS Found C: 36.39 H: 4.94 N: 6.01

Calculated C: 36.97 H: 4.76 N: 5.75

Br: 16.40 S: 6.58

The thiosugar used in the present invention may be incorporated into any of the layers of a light-sensitive photographic material, and is most preferably added to a photographic emulsion which has completed the second ripening. Alternatively, however, the thiosugar may be added before or during the second ripening to control the progress of the ripening, or may have previously been incorporatedinto gelatin or the like starting material for preparation of the emulsion. Furthermore, the thiosugar may be applied to a light-sensitive color photographic material of the so-called protect type in which the thiosugar is made present together with water-insoluble or scarcely water-soluble couplers and is dissolved in a water-inmiscible high boiling solvent and the resulting solution is dispersed in the emulsion. The amount of the thiosugar to be added varies depending on the kind of the emulsion used, the kind of the compound and the desired fog-inhibiting conditions. Generally, however, the thiosugar is used in an amount of mg.-to 2 g. per mole of silver halide and may be added in the form of a solution in a suitable organic solvent such as, for example, methanol, ethanol, acetone or ethyl acetate. In case the thiosugar is desired to be incorporated into an auxiliary layer other than the emulsion layer, it is preferable that the amount of the thiosugar added is controlled so that the total amount thereof per unit area of the resulting photographic material becomes an amount corresponding to the abovementioned amount. If necessary, however, the amount may be increased to a suitable extent.

The aforesaid objects of the present invention can be accomplished more successfully by incorporating into a light-sensitive photographic material the thiosugar in combination with a high molecular compound such as poly-N-pyrrolidone or a copolymer of N-vinylpyrrolidone with another ethylenically polymerizable compound. Typical examples of the above-mentioned high molecular compound are as follows:

Monomer ratio 22. Poly-N-vinyl-2-pyrrolidone 23. N-Vinylpyrrolidone/imidazolinoacrylic 42:58 amide copolymer 24. N-Vinylpyrrolidone/morpholinoacrylic 42:58 amide copolymer 25. NVinylpyrrolidone/piperidinoacrylic 42:58 amide copolymer 26. N-Vinylpyrrolidone/Z-methylimidazolino- 42:58 acrylic amide copolymer 27. N-Vinylpyrrolidone/acrylic diethylamide 42:58 copolymer 28. N-Vinylpyrrolidone/sodium acrylate 75:25 copolymer 29. N-Vinylpyrrolidone/methyl acrylate 42:58 copolymer 30. N-Vinylpyrrolidone/acry1ic amide 75:25 copolymer 31. N-Vinylpyrrodidone/ethyl acrylate :30 copolymer 32. N-Vinylpyrrolidone/acrylic amide/ammonium 40:40:20 maleamate copolymer 33. N-Vinylpyrrolidone/acrylic amide/ 40:40:20 maleic anhydride copolymer 34. N-Vinylpyrrolidone/acrylic amide/ 60:20:20 2-methylimidazole copolymer 3S. N-Vinylpyrrolidonelacrylic amide/ 60:20:20 sodium 2'methylimidazole-3-hydropropionate copolymer 36. N-Vinylpyrrolidone/imidazolinomaleamic 60:40 acid imidazole salt copolymer 37. N-Vinylpyrrolidone/2'methylimidazolino- 60:40 maleamic acid 2-methylimidazole salt copolymer 38. N-Vinylpyrrolidone/2-methylimidazole 60:40 copolymer 39. N-Vinylpyrrolidone/morpholinomethacrylic 20:20:60 acid/methyl methacrylate copolymer 40. N-Vinylpyrrolidone/4-vinylpyridinoN- 42:58 methyl iodide copolymer 41. N-Vinylpyrrolidone/piperidinomaleamic 60:40 acid piperidine salt copolymer 42. N-Vinylpyrrolidone/maleic acid thiourea 60:40 half ammonium salt copolymer 43. N-Vinylpyrro1idone/styrene copolymer 70:30 44. N-Vinylpyrrolidone/piperidino 20:20:60 methacrylate/methyl methacrylate copolymer 45. N-Vinylpyrrolidone/methacrylic amide/ 20:20:60 methyl methacrylate copolymer 46. N-Vinylpyrrolidonelvinyl acetate 70:30

copolymer When any one of the above-mentioned high molecular compounds is incorporated in combination with at least one of the aforesaid thiosugars into a lightsensitive silver halide photographic material, a more excellent antifogging effect can be attained at the time of high temperature processing than in the case where the thiosugar is used alone.

The above-mentioned high molecular compound is dissolved in water or an alkali solution or in such an organic solvent as methanol, ethanol, acetone, ethyl acetate, dioxane or dimethylformamide, and the resulting solution is added to a coating liquid for forming an emulsion layer or an auxiliary layer. The amount of the compound to be used in the above case varies depending on various factors such as the kinds of the compound, the thiosugar used and the layer to which the compound is added, and the like, but is ordinarily within the range from 0.2 to 100 g. per mole of silver solvent as dibutyl phthalate or in such solvent as'chloroforrn, acetone or dimethylformamide and then dispersed in the emulsions, while the couplers having wahalide. In the above case, the amount of the thiosugar to be added is preferably within the aforesaid range. In case the high molecular compound is desired to be incorporated into an internal color photographic material containing an oil-soluble coupler, i.e. a so-called protect type coupler, the compound may be dissolved in a solvent for said coupler or added to a dispersion of said coupler, and then incorporated into, for example, an emulsion layer.

The light-sensitive silver halide photographic materials according to the present invention include photographic materials of various types such as, for example, color photographic materials, black-and-white photographic materials, roentgen photographic materials, other radiation-sensitive photographic materials, lightsensitive printing materials and diffusion transfer type printing materials.

The silver halides used in the present invention include silver chloride, silver bromide, silver chlorobromide, silver iodobromide, etc., and the emulsions containing said silver halides may be optically sensitized by use of various sensitizing dyes such as cyanine dyes, merocyanine dyes or styryl dyes, or may be chemically sensitized by use of such'chemical sensitizers as sulfurcontaining compounds, noble metal salts, polyalkylene oxide derivatives or reducing compounds. Further, as the hydrophilic protective colloids employed as binders in the above case, or as other layer-forming components, gelatin is used, in general, but other known hydrophilic protective colloids, e.g. polyvinyl alcohols and the like, may also be used.

The light-sensitive photographic materials according to the present invention may contain various photographic additives, e.g. coating aids such as lauryl or oleyl monoethers of saponin or polyethylene glycol, or sulfonated or alkylated polyethylene glycol ether salts;' stabilizers or inhibitors such as triazaindolizine type compounds or mercaptotetrazole type compounds; hardeners such as mucobromic acid and the like halogen-substituted fatty acids, or formaldehyde; couplers such as yellow couplers having benzoyl ,acetanilide groups or the like, magenta couplers having pyrazolone nuclei, indazolone nuclei or cyanoacetyl groups, and cyan couplers having phenol or naphthol nuclei (these couplers may have in the active methylene or methine positions such substituents as halogen atoms or allylazo, allyloxy or allylthio groups capable of being released by color development reaction, and'may have in the molecules such non-diffusing groups as long chain alkyl groups or alkylphenoxy groups or such watersoluble groups as sulfonic acid groups or carboxyl groups); and plasticizers such as glycerin and the like. Even when these photographic additives are made present together with the 'thiosugars, they have no detrimental interactions on the photographic properties of the photographic materials.

In incorporating the aforesaid couplers into the lightsensitive photographic materials, there may be adopted the procedures mentioned below. That is, the protect type couplersare dissolved in such high boiling organic ter-soluble groups are dissolved in an alkali solution and then incorporated into the emulsions. On the other hand, some of the couplers are incorporated into color developers and are used as the so-called external couplers.

The light-sensitive color photographic materials are composed of, in general, yellow layer, yellow filter layer, magenta layer, inter layer, cyan layer, antihalation layer and support in this order from the uppermost layer, though the order of the yellow, magenta and cyan layers may sometimes be varied. In this case, each of the color-forming layers such as the yellow layer and the like may be composed of one or two layers.

Supports for the light-sensitive photographic materials according to the present invention are suitably selected in consideration of the application purposes of the photographic materials, and include papers, laminated papers, and natural and synthetic high molecular films of the cellulose acetate and polyester types. If necessary, these supports may be subjected to subbing or the like hydrophilization to make the coating of hydrophilic protective colloid easy and to make the adhesion thereof strong."

The development of the present light-sensitive-silver halide photographic materials as mentioned above is carried out, in general, in the manner mentioned below. Thatis, the black-and-white photographic materials are ordinarily developed with a developer containing such developing agent as Metol, hydroquinone or phenidone; the negative-type color photographic materials are ordinarily developed with a developer containing a color developing agent of the p-phenylenediamine type; and the positive type color photographic materials are ordinarily developed in such a manner that the photographic materials are initially subjected to black-and-white development and then subjected to color development. In the above-mentioned development, the photographic materials of the present invention display satisfactory antifogging effects not only at normal temperature of about 20 to 25C. but also at elevated temperatures'adopted at the time of quick processing. Moreover, even when the processing time is prolonged, the photographic materials are successfully inhibited from formation of color fog, are less in desensitization, and have excellent photographic properties.

The present invention is illustrated in detail below with reference to examples, but the examples are merely illustrative and do not limit the scope of the invention.

EXAMPLE I 5-Methyl-7-hydroxy-1,3,4- 2.0 g/Ag X I mole triazaindolizine 3% Saponin Mucochloric acid 30 ml/Ag X 1 mole 3 mg/g gelatin.

Subsequently, the emulsion was equally divided into four emulsions, and one emulsion was left as it was and in speed and fog. The results obtained were as set forth 10 l Prehardening 5% Sodium dodecylbenzenesulfonate 100 ml.

6. 3% Saponin 60 ml/Ag X 1 mole The thus obtained coating liquid was coated on a cellulose triacetate support to a dry film thickness of 3.5 ,u. and then dried to prepare a photographic film. This film was exposed to a definite light through an optical wedge and then subjected to the following processings: Processings:

40C. 60 sec. 111 Table 1. Neutralization TABLE 1 Amount of'com: sec. sec. sec.

pound (g/Ag Relative Relative Relative Kind of compound 1 mole) speed Fog speed Fog speed Fog None 0.50 100 0.76 100 0.98 Exemplified compound (26). 5.5 100 .46 100 .65 108 .75 Exemplified compound (17). 1.5 100 .13 110 .25 .32 Exemplified compound (26). 5,5 Exemplified compound (17) 1.5 138 (In the above table, the relative speed is a value measured by assuming as 100 the speed ofthe blank sample at each development time.)

From Table 1, it is understood that even when used alone, the thiosugar [the exemplified compound (17)] can successfully inhibit the photographic material from formation of fog without giving any detrimental influence to the speed thereof as compared with the case of the photographic material incorporated with no such compound, and that when the said compound is used in combination with the high molecular compound [the exemplified compound (26)], the degree of increase in fog of the photographic material is markedly low even when the development time is prolonged, and the-time permissible for the high temperature development thereof is broadened to a great extent.

EXAMPLE 2 A high speed silver iodobromide emulsion containing 5 mole percent of silver iodide was subjected to second ripening and incorporated with the below-mentioned photographic additives 1 to (6) in this order to obtain a green-sensitive coating liquid.

1. 3 ,3 -Diethyl-5 ,5 '-diphenyl-9-ethyloxacarbocyanine bromide 0.14 g/Ag X 1 mole. 2. 5-Methyl-7-hydroxy-l,3,4-triazaindolizine 1.4

g/Ag X 1 mole l-Phenyl-5-mercaptotetrazole 0.05 g/Ag X 1 mole 4. Each of such combinations as shown in Table 2 of thiosugars and high molecular compounds used in the present invention.

5. A coupler dispersion prepared by subjecting to a high speed rotary mixer a mixture of the following composition (per Ag X 1 mole): l-(2,4,6-Trichlorophenyl)-3-[3"-(2",4"'-ditert-aminophenoxy acetamide)-benzamide]-5- pyrazolone 54 g. l-(2',4',6-Trichlorophenyl)-3-]3-(2'",4"-ditert-aminophenoxy acetamide)-benzamide]-4- (4"-methoxyphenylazo)-5-pyrazolone 17 g. Tricresyl phosphate 55 g. Ethyl acetate 85 g. 3% Gelatin 700 ml.

3. Color development The time was varied as in Color development bath (pl-l 10.65-10.70):

Benzyl alcohol 5 ml. Sodium sulfite 2 g. Sodium bromide 1.5 g. Sodium hydroxide 12 g. Borax 55 g. 4-Amino-N-ethyl-N-(B- metasulfonamidoethyl)-mtoluidine 3/2 H,SO H,O 5 3. Water to make 1 liter Stopping bath (pH 3.4-3.6):

Sodium acetate 5.3 g Acetic acid 32.0 ml Water to make 1 liter Bleaching bath (pH 6.6-7.0):

Potassium ferricyanide l 12.0 3. Potassium bromide 24.0 g. Disodium phosphate.7H,O 45.0 g.

Monosodium phosphate position (per Ag X 1 mole):

l-Hydroxy-2-[a-(2',

4-di-tert-amylphenoxy)-n-(butyl)']naphthamide 48 g.

Tricresyl phosphate 20 g.

9 10 isg g g gf s: Ethyl acetate 140 g.

- 3% Gelatin 700 ml.

. 0 I Ammonium thiosulfme 120.0 g 5 5. 0.5% Mucochloric acid 80'ml/Ag X 1 mole Potassium metabisulfite 20.0 g. i The thus obtalned coatmg liquid was coated on a celmake, 1 lulose triacetate support to a dry film thickness of 4 p. andthen dried to prepare a photographic film. This stablhzatlon bath film was exposed to a definite light through an optical Fmmalm 40%) g 3.0 ml. lllvfsielgrrllcgisthen sub ectedto the following processmgs: Kodak Stabilizer MX-707 (10% 10.0 ml. l Water to make I liter 1 l. Prehardening 50C. 35 sec. 2. Neutralization 35 The relative speed and fog of each film after the pro- First development The time was cesslngs were as set forth 1n Table 2. varied as in Table 3 TABLE 2 Developed for I Developed for Developed for l min. 2 min. 3 min.

Kind and amount (g/Ag X 1 mole) Kind and amount (g/Ag X 1 mole) Relative Relative Relative of thiosugar of high molecular compound speed Fog speed Fog speed Fog 100 0.20 '100 0.30 100 0.52 Exemplified compound (22) 0.34 I00 .l8 100 .26 I03 .40 Exelnplified compound .(5) 0.7 I00 .l3 I01 .18 H0 .24 Exemplified compound (5) 0.7 Exemplit'led compound (22) 0.34..... 100 .06 105 .08 I05 .08 Exemplified compound (9) 0.7 98 .12 100 .18 I05 .22 Exemplified compound (9) 0.7 Exemplified compound (22) 0.34..... 96' .07 102 .08 100 .10

As is clear from Table 2; it is understood that even Fim PP TS 35 h h. d .d b 5. Water-washing 35 w en the t losugar ls use a one, consl era e anti og- 3O Supplementary exposure Abom IO glng effect can be seen, but when thethlosugar used 7. Color development 120 in combination with poly-N-vinylpyrrolidone, mark- 3' 552222 5532? edly high antifogging effect can be'attained without acto. Bleaching ll. Fixing 3s eompanymg desensltlzatlon and, particularly, the varla 1 z watepwashing 60 tlon ln fog'value due to the development time varlatlon 35 Stabilization u I 35 becomes smaller. (The operations 5-l3 may be effected under an ordinary room light.)

EXAMPLE 3 A high speed silver iodobromid'eemulsi'on containing Formulations 3.5 mole percent of silver iodide was-subjected to sec- 40 1 Same as in Example 2 except the first development on'd ripening and incorporated with the belowbath. First development bath (pl-l 10.1-10.3): mentioned photographic additives (1') to (5') in this order to obtain a red-sensitiveemulsion.. g

l. 3,3'-Diethyl-5,5'-dichloro-9-ethyls m x et ph phate 2.8 g.

7 e10 thlacarbocyanlne lodlde 0.12 g/Ag X 1 mole Sodium suit-e soogg 2. Each of such combinations as shown in Table 3 of Sodium carbonate 30.0 g.

Hydroquinone 6.0 g. thlosugars and high molecular compounds used in the Potassium bromide M present invention. Sodium thiocyanate 1.3 g.

Sodium hydroxide 2.0 g. coupler dlsperslon Prepared by sublecfmg to a Potassium iodide (0.1%. solution) 60 ml. high rotary mlxer a mlxture of the following comwater to make 1 The relative-speed and maximum density (D-max) of each film after the processings were as set forth in Table 3'.

TABLE 3 Kind and amount (g/AgX 1 mole) of thiosugllr of high molecular compound Kind and amount (g/Ag X 1 mole) Exemplified compound (30) 5.5 Exemplified compound (ll) 2. g

0 Exemplified compound (1 2.0 Exemplified compound (30) 5.5

Exemplified compound (37) 2.0......

Exemplified compound (16) 1.5 Exemplilled compound (16) 1.5

. Exemplified compound 37) 2.0

As is clear from Table 3, it is understood that in color reversal treatment also, an antifog ging effect in the first development is seen by use of the thiosugar, with the result that the D-max value is maintained as it is without any substantial decrease in relative speed. This effect can be more enhanced by using the thiosugar in combination with containing a high molecular compound, e.g. N-vinylpyrrolidone.

EXAMPLE 4 A light-sensitive color printing paper having a protective layer, a red-sensitive layer, an inter layer, a greensensitive layer, an inter layer, a blue-sensitive layer and a support in this order from the upper-most layer was prepared by successively coating emulsions of the below-mentioned compositions on a baryta paper to form respective layers. 1. Bluesensitive layer A silver chloroiodobromide emulsion containing 1.3 mole percent of silver iodide and 15 mole percent of silver bromide was subjected to second ripening and successively incorporated with such photographic additives as mentioned below.

a-[4-(B-Carboxy-B-octadecyl propionylamide)- benzoyl]-3-carboxy-6-methoxyacetanilide 100 g. 3% Saponin 80 ml.

0.5% Mucochloric acid 110 ml.

Subsequently, the emulsion was coated on a baryta paper to a dry film thickness of 4.0 p. and then dried to form a blue-sensitive layer.

2. lnter layer An emulsion of the composition shown below was coated on the above-mentioned blue-sensitive layer to a dry film thickness of l p. and then dried to form an inter layer.

2% Gelatin 960 ml.

v 3% Saponin 30 ml.

0.5% Mucochloric acid 35 ml.

Grssnrs nst ys laye H A silver chlorobromide emulsion containing 15 mole percent of silver bromide was successively incorporated with such photographic additives as mentioned below. 7

3 ,3 -Diethyl- ,5 '-diphenyl-9-ethyl-oxacarbocyanine bromide 0.28 g. l-Phenyl-3-( B-carboxy-B-octadecyl-propionylamide)-5-pyrazolone 80 g. 3% Saponin 80 ml. 0.5% Mucochloric acid 110 ml.

Subsequently, the emulsion was coated on the abovementioned inter layer to a dry film thickness of 3.5 p. and then dried to form a green-sensitive layer. 4. lnter layer An emulsion of the same composition as in the case of the aforesaid inter layer (2) was coated on the above-mentioned green-sensitive layer to a dry film thickness of l p. and then dried to form an inter layer. 5. Red-sensitive layer A silver chlorobromide emulsion containing mole percent of silver bromide was subjected to second ripening and successively incorporated with such photographic additives as mentioned below.

thiacarbocyanine bromide 0.25 g.

N-[ 3-(B-Carboxyl-B-octadecyl propionylamide) promentioned inter layer to a dry film thickness of 3.5 p.

and then dried to form a red-sensitive layer. 6. Protective layer:

An emulsion of the same composition as in the case of the aforesaid inter layer (2) was coated on the above-mentioned red-sensitive layer to a dry film thickness of l y. and then dried to form a protective layer.

The light-sensitive color printing paper prepared in the above manner was used as'a control sample.

On the other hand, a sample was prepared in the same manner as above, except that a combination of 0.85 g/Ag X 1 mole of the exemplified compound (7) and 2.3 g/Ag X l mole of the exemplified compound 22) (PVPK-ZO Powder, manufactured and sold by General Aniline and Film Corporation) was incorporated into each of the blue-sensitive, green-sensitiveand red-sensitive emulsions.

These samples were individually subjected to the following processings:

Processings:

1. Color development 30C. The development time was varied as shown in Table 4. 2. Stop-fix-hardening 30 sec. 3. Water-washing 30 4. Bleach-fixing 2 min. 5. Water-washing 3 Formulations:

Color development bath (pH 10.8-1 1.0):

Sodium hexametaphosphate 2.0 g. Hydroxylamine sulfate 4.0 g. Sodium sulfite 4.0 g. Potassium carbonate 60.0 g. Potassium bromide 0.5 Sodium hydroxide 6.0 8.0 g 4-Amino-N-ethyl-N-(B-methane- -sulfonamidoethyl)-m-toluidine 3/2 H,SO H,O 8.0 Water to make 1 liter Stop-fix-hardening bath (pl-l 4.3 i 0.1):

The variation in fog stability of each sample due to the variation of development time was as set forth in Table 4.

TABLE Developed for 3 min.

Developed for 4 min.

Sample Du D D D D1,- D D D1; 1.-

(ontrol sample 0.02 0.03 0.02 0.10 0.09 0.13 022 i 0.18 0.25 Sample of the present invention .02 .02 .03 .03 .04 .04 .05 .05 .07

- (In the table; D =fog of blue density, D =fog of green density. Dn=fog of red density.)

From Table 4, it is understood that the light-sensitive respect to the u) ts) atomscolor printing material according to the present invention is successfully inhibited from formation of fog.

What we claim is: I l. A photographic element comprising a support having thereon one or more layers at least one of which is a light-sensitive silver halide emulsion layer. said element contains a thiosugar having the formula:

O l l i u) C(2) m) o in R2 7 H OCOCl-l OCUCH OCOCH H wherein R" is a hydrogen atom, an alkyl group, or a group of the formula 4. A photographic element as claimed in claim 1, wherein said thiosugar is one or two members selected from the group consisting of l-mercapto-D-glucose tetraacetate, l-mercapto-D-mannose tetraacetate, acetylthio-D-ribose triacetate, l-acetylthio-D-mannose tetraacetate, butyl tetraacetyl-D-glucose xanthate, tetraacetyl-D-glucose isothiuronium bromide, l-mercapto-D-xylose t riacetate, ethyl triacetyl-D-xylose xanthate and l-methylthio-D-glucose tetraacetata.

5. A photographic element as claimed in claim 1, wherein said N-vinylpyrrolidone polymer is one or two members selected from the group consisting of poly-N-vinyl-2-pyrrolidone, N-vinylpyrrolidone/2- methylimidazolinoacrylic amide copolymer, 'N-vinylpyrrolidone/acrylic amide copolymer, N-vinylpyrrolidone/2-methylimidazolino-maleamic acid -2- methylimidazole salt copolymer and N- vinylpyrrolidone/morpholinoacrylic amide copolymer.

6. A photographic element as claimed in claim 4, wherein said thiosugar is butyl tetraacetyl-D-glucose xanthate, l-mercapto-D-glucose tetraacetate, l-acetylthio-D-mannose tetraacetate, tetraacetyl-D-glucose iso-thiuronium bromide, l-acetylthio-D-ribose triacetate or l-mercapto-D-mannose tetraacetate and sakd N-vinylpyrrolidone polymer is poly-N- vinylpyrrolidone.

7. A photographic element as claimed in claim 1, wherein said thiosugar is used in an amount of 10 mg. to 2 g. per mole of silver halide.

8. A photographic element as claimed in claim 1, wherein 5-methyl-7-hydroxy-l,3,4-triazaindene is further incorporated into said silver halide emulsion layer.

9. A photographic element as claimed in claim 1, wherein l-phenyl-S-mercapto-tetrazole is further incorporated into said silver halide emulsion. 

2. A photographic element as claimed in claim 1 wherein an N-vinyl pyrrolidone polymer is present in said silver halide emulsion layer.
 3. A photographic element as claimed in claim 1, wherein said thiosugar is one of the stereoisomers with respect to the C(1) to C(5) atoms.
 4. A photographic element as claimed in claim 1, wherein said thiosugar is one or two members selected from the group consisting of 1-mercapto-D-glucose tetraacetate, 1-mercapto-D-mannose tetraacetate, 1-acetylthio-D-ribose triacetate, 1-acetylthio-D-mannose tetraacetate, butyl tetraacetyl-D-glucose xanthate, tetraacetyl-D-glucose isothiuronium bromide, 1-mercapto-D-xylose triacetate, ethyl triacetyl-D-xylose xanthate and 1-methylthio-D-glucose tetraacetata.
 5. A photographic element as claimed in claim 1, wherein said N-vinylpyrrolidone polymer is one or two members selected from the group consisting of poly-N-vinyl-2-pyrrolidone, N-vinylpyrrolidone/2-methylimidazolinoacrylic amide copolymer, N-vinylpyrrolidone/acrylic amide copolymer, N-vinylpyrrolidone/2-methylimidazolino-maleamic acid 2-methylimidazole salt copolymer and N-vinylpyrrolidone/morpholinoacrylic amide copolymer.
 6. A photographic element as claimed in claim 4, wherein said thiosugar is butyl tetraacetyl-D-glucose xanthate, 1-mercapto-D-glucose tetraacetate, 1-acetylthio-D-mannose tetraacetate, tetraacetyl-D-glucose iso-thiuronium bromide, 1-acetylthio-D-ribose triacetate or 1-mercapto-D-mannose tetraacetate and said N-vinylpyrrolidone polymer is poly-N-vinylpyrrolidone.
 7. A photographic element as claimed in claim 1, wherein said thiosugar is used in an amount of 10 mg. to 2 g. per mole of silver halide.
 8. A photographic element as claimed in claim 1, wherein 5-methyl-7-hydroxy-1,3,4-triazaindene is further incorporated into said silver halide emulsion layer.
 9. A photographic element as claimed in claim 1, wherein 1-phenyl-5-mercapto-tetrazole is further incorporated into said silver halide emulsion. 